Max size of string data that can be passed in intents [duplicate]

Question

Is there a max limit to the string data that can be passed in intent extra? How much data can the below String str hold?

intentI1.putExtra("MyString", str);

Answer 1

My tests on Android API Level 24:

            Intent intent = new Intent(MainActivity.this, DetailActivity.class);
//            intent.putExtra("extra", new byte[1024 * 1024]); // 1024 KB = 1048576 B, android.os.TransactionTooLargeException
//            intent.putExtra("extra", new byte[1024 * 512]); // 512 KB = 524288 B, android.os.TransactionTooLargeException
//            intent.putExtra("extra", new byte[1024 * 506]); // 506 KB = 518144 B, android.os.TransactionTooLargeException
//            intent.putExtra("extra", new byte[1024 * 505]); // 505 KB = 517120 B, android.os.TransactionTooLargeException
            intent.putExtra("extra", new byte[1024 * 504]); // 504 KB = 516096 B, OK
            startActivity(intent);

android.os.TransactionTooLargeException https://developer.android.com/reference/android/os/TransactionTooLargeException.html

Because I need to send large amount of data to the activity, I am using the following solution (i know, its not perfect, but it can help):

public class ExtendedDataHolder {

    private static ExtendedDataHolder ourInstance = new ExtendedDataHolder();

    private final Map<String, Object> extras = new HashMap<>();

    private ExtendedDataHolder() {
    }

    public static ExtendedDataHolder getInstance() {
        return ourInstance;
    }

    public void putExtra(String name, Object object) {
        extras.put(name, object);
    }

    public Object getExtra(String name) {
        return extras.get(name);
    }

    public boolean hasExtra(String name) {
        return extras.containsKey(name);
    }

    public void clear() {
        extras.clear();
    }

}

Then in MainActivity

ExtendedDataHolder extras = ExtendedDataHolder.getInstance();
extras.putExtra("extra", new byte[1024 * 1024]);
extras.putExtra("other", "hello world");

startActivity(new Intent(MainActivity.this, DetailActivity.class));

and in DetailActivity

ExtendedDataHolder extras = ExtendedDataHolder.getInstance();
if (extras.hasExtra("other")) {
    String other = (String) extras.getExtra("other");
}

Answer 2

Checkout this post which says 1MB is a limit. Also checkout this one.

There is also a report on issues site.

The real question is: why pass a 1M data between activities? Perhaps a better way to achieve what you want is to persist this data and pass an identifier instead.

Answer 3

Because startActivity will finally pass the whole Intent data to ActivityManagerService through Binder. And the Binder transaction buffer has a limited fixed size, currently 1Mb. Google Ref